The effectiveness of interventions during the first 1,000 days to improve energy balance‐related behaviors or prevent overweight/obesity in children from socio‐economically disadvantaged families of high‐income countries: a systematic review

Summary This narrative systematic review examined effectiveness of interventions during pregnancy and up to 2 years of age in improving energy balance‐related behaviors or prevent overweight/obesity in children from families experiencing socio‐economic disadvantage. We identified 24 interventions, from 33 articles, since 1990. Overall, despite their heterogeneity and variability in internal and external validity, there was some evidence of beneficial impact of interventions on obesity risk (4/15), and associated behaviors, e.g.: breastfeeding (9/18), responsive feeding (11/16), diet (7/8), sedentary (1/3) and movement (4/7) behaviors, and sleep (1/2). The most effective interventions aimed at promoting breastfeeding commenced antenatally; this was similar for the prevention of obesity, provided the intervention continued for at least 2 years postnatally and was multi‐behavioral. Effective interventions were more likely to target first‐time mothers and involve professional delivery agents, multidisciplinary teams and peer groups. Among ethnic/racial minorities, interventions delivered by lay agents had some impact on dietary behavior but not weight outcomes. Co‐creation with stakeholders, including parents, and adherence to theoretical frameworks were additional ingredients for more pragmatic, inclusive, non‐judgmental, and effective programs. The growing body of evidence on obesity prevention interventions targeting families experiencing socio‐economic disadvantage is promising for reducing early inequalities in obesity risk.


Rationale
3 Describe the rationale for the review in the context of existing knowledge. Pages 2 and 3 (Introduction section) Objectives 4 Provide an explicit statement of the objective(s) or question(s) the review addresses. Page 2 (end of Introduction section)

METHODS
Eligibility criteria 5 Specify the inclusion and exclusion criteria for the review and how studies were grouped for the syntheses.
Pages 3 and 4 (2.1. Study selection criteria section) and Selection process 8 Specify the methods used to decide whether a study met the inclusion criteria of the review, including how many reviewers screened each record and each report retrieved, whether they worked independently, and if applicable, details of automation tools used in the process.
Page 5 (2.3. Study selection section) Data collection process 9 Specify the methods used to collect data from reports, including how many reviewers collected data from each report, whether they worked independently, any processes for obtaining or confirming data from study investigators, and if applicable, details of automation tools used in the process.
Page 5 (2.4. Data extraction section) Data items 10a List and define all outcomes for which data were sought. Specify whether all results that were compatible with each outcome domain in each study were sought (e.g. for all measures, time points, analyses), and if not, the methods used to decide which results to collect.
Page 5 (2.4. Data extraction section) and Table 1 Section and Topic Item # Checklist item Location where item is reported 10b List and define all other variables for which data were sought (e.g. participant and intervention characteristics, funding sources). Describe any assumptions made about any missing or unclear information.
Page 5 (2.4. Data extraction section) Study risk of bias assessment 11 Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) used, how many reviewers assessed each study and whether they worked independently, and if applicable, details of automation tools used in the process.

Quality assessment section)
Effect measures 12 Specify for each outcome the effect measure(s) (e.g. risk ratio, mean difference) used in the synthesis or presentation of results.
NA (narrative review, see page 6, 2.6. Synthesis of results section) Synthesis methods 13a Describe the processes used to decide which studies were eligible for each synthesis (e.g. tabulating the study intervention characteristics and comparing against the planned groups for each synthesis (item #5)).
13b Describe any methods required to prepare the data for presentation or synthesis, such as handling of missing summary statistics, or data conversions.
13c Describe any methods used to tabulate or visually display results of individual studies and syntheses.
13d Describe any methods used to synthesize results and provide a rationale for the choice(s). If metaanalysis was performed, describe the model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software package(s) used.
13e Describe any methods used to explore possible causes of heterogeneity among study results (e.g. subgroup analysis, meta-regression).
13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results.

Reporting bias assessment
14 Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases).

Quality assessment section)
Certainty assessment 15 Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome.

Study selection
16a Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included in the review, ideally using a flow diagram.
Pages 6 and 7 (3.1. Identification of studies section) and Figure 1. PRISMA flow chart resulting from the search strategy 16b Cite studies that might appear to meet the inclusion criteria, but which were excluded, and explain why they were excluded. 17 Cite each included study and present its characteristics. Pages 7-11 (3.2. Study characteristics and 3.3. Interventions' characteristics sections) and Table 2 Risk of bias in studies 18 Present assessments of risk of bias for each included study. Table S1 Results of individual studies 19 For all outcomes, present, for each study: (a) summary statistics for each group (where appropriate) and (b) an effect estimate and its precision (e.g. confidence/credible interval), ideally using structured tables or plots.
Pages 11-13 (3.4. Impact on outcomes section) and Tables 3  and 4 Results of syntheses 20a For each synthesis, briefly summarise the characteristics and risk of bias among contributing studies.
20b Present results of all statistical syntheses conducted. If meta-analysis was done, present for each the summary estimate and its precision (e.g. confidence/credible interval) and measures of statistical heterogeneity. If comparing groups, describe the direction of the effect.

NA (narrative review)
20c Present results of all investigations of possible causes of heterogeneity among study results.
20d Present results of all sensitivity analyses conducted to assess the robustness of the synthesized results.

Section and Topic
Item # Checklist item Location where item is reported Reporting biases 21 Present assessments of risk of bias due to missing results (arising from reporting biases) for each synthesis assessed.
Pages 13-15 (3.5. Internal validity and 3.6 External validity sections) and Tables S1 and S2 Certainty of evidence 22 Present assessments of certainty (or confidence) in the body of evidence for each outcome assessed.